1. Field of the Invention
The present invention relates to a door locking handle assembly of a pull-out and side-swinging lever-action type. The door locking handle assembly is used in a plugboard box and the like. In operation, the retractable handle of the assembly is pulled out of its casing and side-swung through a predetermined angle to permit a catch plate of the assembly to be disengaged from a receiving portion of a stationary frame element.
2. Description of the Prior Art
In a conventional door locking handle assembly of a pull-out and side swinging lever-action type disclosed in Japanese Utility Model Laid-Open No. Hei 3-66369: a cylinder portion is provided in a base-end portion of a casing fixedly mounted on a door; a locking shaft is inserted in the cylindrical portion and rotatably mounted therein but not axially slidable therein; a catch plate is fixedly mounted on a rear-end portion of the locking shaft; a retractable handle folds into a front concave portion of the casing, and has its base-end portion pivoted to a front-end portion of the locking shaft through a first cross pivot; a biasing spring for swingably biasing the retractable handle in its projecting direction on the first cross pivot, the biasing spring being mounted between the locking shaft and the handle; a push button has its leg portion projected from its rear surface, and is provided with a locking hole and an engaging-hook portion in a front-end portion of the leg portion, the push button being connected with a front-end portion of the handle through a second cross pivot; a position-keeping spring disposed between the handle and the push button, and forces the push button to align with the handle along an extension line thereof; a lock unit is fixedly embedded in a lock-receiving portion provided in a front-end portion of the casing; and, a latch element is so arranged as to be interlocked with a rotor of the lock unit, and is biased forward towards the leg portion of the push button by a return spring to have a front-end portion of the latch element engaged with the locking hole so that the handle is locked up in its retracted position.
However, in the conventional door locking handle assembly described above, there is a fear that the handle is not locked up in its retracted position when the handle is not completely pushed into the casing, because the push button (which is swingably mounted on the front-end portion of the handle through the second cross pivot) tends to excessively swing away from the latch element so that the locking hole of the push button does not engage with the front-end portion of the latch element, which permits the handle to swing back on the first cross pivot in the handle's projecting direction under the influence of the resilient force exerted by the biasing spring.
Further, in another conventional door locking handle assembly of a pull-out and side swinging lever-action type disclosed in Japanese Utility Model Laid-Open No. Sho 63-198764: a cylinder portion is provided in a base-end portion of a casing fixedly mounted on a door; a locking shaft is inserted in the cylindrical portion and rotatably mounted therein but not axially slidable therein; a catch plate is fixedly mounted on a rear-end portion of the locking shaft; a retractable handle folds into a front concave portion of the casing, and has its base-end portion pivoted to a front-end portion of the locking shaft through a first cross pivot; a biasing spring for swingably biasing the retractable handle in its projecting direction on the first cross pivot, the biasing spring being mounted between the locking shaft and the handle; a locking hole is provided in a finger-engaging projection portion of a front-end portion's rear surface of the handle; a lock unit is fixedly embedded in a lock-receiving portion provided in a front-end portion of the casing; and, a latch element is so arranged as to be interlocked with a rotor of the lock unit, and is biased forward towards the finger-engaging projection portion by a return spring to have a front-end portion of the latch element engaged with the locking hole so that the handle is locked up in its retracted position.
However, in the conventional door locking handle assembly described above, there is a fear that the front-end portion of the handle hits the user's fingers. Namely, when the user inserts a key into the lock unit to move its rotor in an unlocking direction thereof, the latch element slidably moves backward to be free from the locking hole of the handle side, so that the handle is immediately projected forward in a swinging manner under the influence of a resilient force exerted by a biasing spring, whereby the front-end portion of the handle hits the user's fingers. In order to prevent the handle from hitting the user's fingers, it is sufficient to dispose the lock unit in a position far away from the front-end portion of the handle. However, naturally, this causes the entire length of the casing to increase. In order to set a sufficient interval between the lock unit and the handle without increasing the entire length of the casing, it is sufficient to decrease the handle in length. However, when a grip portion of the handle is extremely shortened, the handle is impaired in operability. Consequently, such shortening of the grip portion of the handle is not an adequate solution.